Larking about...

Thursday saw four sites being worked, and lots of interesting birds ringed.

Kev decided to try his first thermal imaging session of the year at Patshull. Here is his account of the session ( which turned into two sessions!):-

Starting at 3am(!), in just the first harvested field surveyed, a Grey Partridge was caught and ringed, with a second bird seen - our first record of this declining farmland species at the site. Not a bad start!

Over the course of the next couple of hours, a dozen or so Skylark were noted, with two of this year's youngsters also caught and ringed.

Both of these species undergo a complete post-breeding moult, progressively shedding feathers and growing new ones to replace them. As can be seen from the images of the open wings, these birds are moulting the primary and secondary feathers from the centre of the wing- both inwards and outwards along the rear edge of the wing. The Skylark especially shows its new feathers in different stages of growth, with the shortest and youngest still in their protective waxy sheaths or 'in pin'.

The pale tips to many of the feathers show this bird to be a juvenile

This Grey Partridge also shows a single buff line down the centre of each smaller and more chestnut wing feather (coverts), indicating this bird to be a male - a female would also exhibit buff bars at right angles to each buff line.

By dawn, we'd moved to a brand new ringing location on the estate and set some nets in eager anticipation of what else might be caught. By mid morning a further 34 birds had been ringed, including 9 Blackcap, 3 Chiffchaff, 3 Whitethroat and 2 Garden Warbler. 

This adult male Whitethroat is also going through a post- breeding moult. Even in the closed wing, the longest primary can be seen to be more worn and pointed, and therefore older, than the inner ones; at the bend of the wing, some of the short feathers (coverts) are in pin; and the old central tail feathers have been retained whilst the newer, outer and currently shorter tail feathers are still growing.

Young Blackcaps have brown crowns (much like adult females) when they leave the nest, presumably to avoid any perceived threat by their father. However, within a few weeks of fledgling, youngsters moult their crowns (and other feathers) and can be start to be sexed. 

Ben was out at his new site but a couple of technical hitches reduced what was looking like being a big catch. Nevertheless he had 37 new birds--mostly warblers--one of which was a smart juvenile Lesser Whitethroat. We are out on Saturday evening at the site looking to see if there is a roost of Swallows.....if there is we will report on this next week.

A small team entertained a visiting guest, Mike, at Belvide on Thursday morning. In truth, after two good catches there already this week, we were expecting a fairly modest catch, but one which would showcase the site. As it turned out we caught another 100 new birds--again mostly migrants, with 34 Sedge Warblers being the most numerous. Two dollops of icing on the cake were our second and third Lesser Whitethroat of the season and, best of all our second Grasshopper Warbler of the season.

If you check back to our last post, we show a picture of an adult 'Gropper' showing the wear and tear on the feathers. In contrast here are pictures of the wing and tail feathers of Thursday's bird which was a juvenile. The relevant feathers are all brand new and in very good condition:-

A much better pic of the characteristic round tail of a 'Gropper'

And a beautiful picture of the pristine wing feathers.

Later on last evening we had a message from Pat out at Siskin City, near Welshpool, letting us know that although he didn't catch any Siskin yesterday, he had a decent catch of other common finches--especially Chaffinch and Greenfinch.

So--all in all a very successful day for the group with just under 200 new birds ringed--most of which in one way or another are very interesting and potentially might provide some useful data on migration routes. 

Well done everyone--more to come over the weekend I hope.......